Crossing Continents speaks to a German doctor who was so moved by the suffering of North Koreans that he now dedicates his life to helping them escape.

Norbert Vollertsen is worried.

He is worried about being expelled by South Korea. He is worried about being assassinated by North Korean agents. And he worries about the Chinese Government.

He moves around, from internet café, to internet café, city hall to tea room.

"Better not stay in any one place too long," he says.

Only four years ago, Mr Vollertsen was living a comfortable existence as a medical practitioner in Germany.

But in 1999, he decided to uproot to North Korea to work for a German aid organisation.

For half a century the so-called "hermit kingdom" has been one of the most repressive countries in the world.

And yet Mr Vollertsen quickly became the darling of the government, after donating some of his own skin to help a burns victim.

I saw the conditions in the hospitals. There is no medicine, no food, no heating system, no running water, no soap, no blankets, nothing

Norbert Vollertsen

"I did it to show friendship to the ordinary people of North Korea," he says.

He became the first Westerner to receive the Friendship Medal of the North Korean people.

And he also got a VIP passport, enabling him to travel around the country virtually unhindered.

"But I abused my freedom," he says.

Collecting the evidence

With his unique access to the countryside, he travelled the length and breadth of the country.

"I realised there are two different worlds in North Korea," he told the programme.

"One is for the elite - who enjoy a fashionable lifestyle, casinos, nightclubs, nice hotels.

"The other is for ordinary people in the countryside. They are starving.

"And I saw the conditions in the hospitals. There is no medicine, no food, no heating system, no running water, no soap, no blankets, nothing."

When a US congressman visited North Korea, Mr Vollertsen handed him a thick dossier of evidence and was summarily expelled.

Risky business

He now lives in the South Korean capital, Seoul, and is part of a clandestine network of people assisting those who flee North Korea.

Nobody knows the full scale of this secret exodus.

We failed to act when we found out about the Jews and the concentration camps

Norbert Vollertsen

It is estimated that there are up to 300,000 North Koreans living in China.

There is a bounty on their heads, and they face betrayal and arrest at every moment.

Those captured can be executed upon return. Their families may be punished too.

Very few make it to South Korea. In 2002, just over 1,000 did so.

Mr Vollertsen says that after being thrown out of Pyongyang, the North Korean capital, he could have gone back to Germany.

But in the end he decided to continue his humanitarian activities, operating from Seoul.

"You know about German history. We failed to act when we found out about the Jews and the concentration camps. I do not want to make the same mistake twice.

"What shall I tell my own boys? That I knew about crimes against humanity but went back to Germany, lived under nice conditions and forgot about the starving conditions. No, I will not do that."

Personal cost

His political activities have, nonetheless, cost him his marriage.

"My wife blamed me for not taking care of my family.

"She said my vision, my goals, my projects, were worth much more to me. And afterwards, I realised she was right."

"I do not want to sacrifice my family. But I know my wife and her partner are taking care of my children, and that they are safe and healthy. But the North Korean children are not."

Mr Vollertsen is not overly popular with the South Korean Government.

I will never forget the eyes of the children who were dying

Norbert Vollertsen

North Korean defectors receive a relatively generous financial package when they arrive, but the country's so-called "sunshine policy" of engagement with the North, makes Mr Vollertsen's activities something of an embarrassment.

The South Koreans keep close tabs on the German. He has even been followed.

Critics of his tactics say that his very public campaign has prompted a Chinese clampdown and made the already precarious position of the North Korean refugees even worse.

But Mr Vollertsen insists it his duty to speak up.

"I will never forget the eyes of the children who were dying. They cannot cry any more. They cannot laugh any more. They have no emotional reaction. They have no hope."

BBC Radio 4's Crossing Continents will be broadcast on
Thursday, 24 April, 2003 at 1102 BST.